Apparatus for drawing sheet glass



April 15, 1930. J. A. WATT APPARATUS FOR DRAWING SHEET GLASS 2 Sheets-Sheet 1 Filed April 4, 192

INVENTOR gym a Wm 1 i JOHN A. warm,

mesa Apr. 15,1930

UNITED sT T-EsrArENr Orries or cmnxsnuno, wnsr vmemrn; assreno'n sro rrr'rsnuaen Purl: Grass COMPANY, a conrona'rron orzennnsynvmm arrana'rns FOB ."DRAWING: 'snnn'r cuss Application filed April 4, 1928. a Serial No. 887,209.

The invention relates to apparatus for drawing sheet glass. It has for its object the provision of means for preventing the sheet being drawn from thinning along linesinward from the. side edges of the glass, but adjacent thereto, in the use of thelSlingluif drawing process and apparatus, as disclosed in the Slingluif Patent No. 1,549,513. In the use of this apparatus, there is a tendency m of the sheet to thin as indicated at a in Fig.

i of Fig. 2. Fig.

4, which shows a horizontal section of the marginal portion of a sheet produced on the Slinglufl' machine. This thinning of the sheet tends to increase the percentage of the breakage, and requires that a wider margin of the edge shall be trimmed oif than would otherwisebe the case. The present invention v is designed to remedy this condition. One

embodiment of'the invention is illustrated in the accompanying drawings, wherein Figure 1 is a'vertic'alsection on the line 1-1 2'is a vertical section on the line II- -II of ig'. 1. Fig. 3 'isa plan-view of the draw bar to which the invention particularly relates. -And Fig. 4 is an enlarged hori-.

zontalsection through the edgefof a sheet produced on the Slinglufi machine not'employipg the improvement to which the present invention relates.

Referring to the drawings, 1" is the end of melting tank, preferably of-the regenerator type; 2 is the forehearth or drawing tank I communicating at its end'with the melting tank; 3 is the lower end of the drawing apparatus provided with aserifes of rolls. for

v drawing the sheet, such rolls being driven from the gears 4-4, 4 -4, etc.; 5 is the glass sheet which is being drawn from the fore hearth; and 6 is the draw bar to which the in vention particularly relates. The drawbar is provided with the usual slot 7 extending from f one end ofthe bar to the other and with a pair of. projections 8, 8' at eachend projecting upwardly toward the' surface of the bath,-as indicated in Fig. 2. These. projections are locatedjust beneath the marginal portions a, a

of thesheet, which are normally drawn some;

. what thin inthe Slingluif operatiomas-heretofore referred toan'd .as'indicated'in Fig. 4, whereinthe portions a are located about 5. inches fromthe extreme edges ofthe sheet.

The projections 8, 8 increase the. chilling or shielding effect of the draw bar beneath the margina% portions ofthe sheet and cause these edges to hicken up so that the breaka e is-reduced and the sheet may betrimmed c oser to the edge than would otherwise be the case,

thus increasing the production of the machine. r

,What I claim is:

1. The combination with a machine for drawing a glasssheet continuously from a bath of molten glass, of a'draw bar of refraetory material submerged in the glass beneath the line of generation of the sheet having projections located directly beneath the marginal portions of thesheet and beneath the surface ,fractory material submerged inthe glass beneath the line of generation of the sheet and extending entirely across the bath with humps or shoulders located directly beneath the outer portions of the sheet a short distance inward from the extreme outer edges thereof,

said humps approaching nearer to the surface of thebath than do theportions of the bar lying on both sides "of the projections.

In testimony whereof, I have hereunto sub scribed my name this 28 da of Fell, 1928. K JO NA.WATT. 

